First of all, you need to clean all the previous Ajax messages inserted after a form submission. Then you build up
your query string and pass it to the ajax() object, also specifying the type of your request, the URL of the
server-side script and the data passed with your query (in this case, it's a GET query). If the request is successful, you insert
the result into an HTML element. Be aware that you have also to prevent the default action of the form from happening: if
you don't do so, your browser will open the page specified in the action attribute of your form.

If you want to test this example, try to insert some valid values such as CSS, DOM and XML and then some dummy
text. You can see the final result here.